A) Field of the Invention
The present invention relates to an ultraviolet-emitting material and an ultraviolet light source.
B) Description of the Related Art
It is known that a magnesium oxide (MgO) crystal is used as a correcting standard sample for an electron beam excitation-type vacuum ultraviolet-emitting measurement apparatus (see Japanese Unexamined Patent Application Publication No. 2011-232242, for example). According to the description in Japanese Unexamined Patent Application Publication No. 2011-232242, light emission with a wavelength from 170 nm to 200 nm can be obtained by irradiating the magnesium oxide single crystal, which has been made to grow by an electrofusion method, with an electron beam.
However, intensity of the light emission from the MgO crystal that is obtained by the electron beam excitation is low for usage as a light source.